From: Tim Kientzle <kientzle@gmail.com>
Date: Thu, 27 Aug 2009 04:25:42 +0000 (-0400)
Subject: Reverse-merge r1394 from release/2.7 branch:  Fix sparse
X-Git-Tag: v2.8.0~409
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=95cfd8e4a7cc37f2fdc372b65e514f4eb75ace6c;p=thirdparty%2Flibarchive.git

Reverse-merge r1394 from release/2.7 branch:  Fix sparse
file handling on systems that lack ftruncate().

SVN-Revision: 1395
---

diff --git a/libarchive/archive_write_disk.c b/libarchive/archive_write_disk.c
index 99e15a108..36853370e 100644
--- a/libarchive/archive_write_disk.c
+++ b/libarchive/archive_write_disk.c
@@ -696,15 +696,18 @@ _archive_write_finish_entry(struct archive *_a)
 		}
 #endif
 		/*
-		 * Explicitly stat the file as some platforms might not
-		 * implement the XSI option to extend files via ftruncate.
+		 * Not all platforms implement the XSI option to
+		 * extend files via ftruncate.  Stat() the file again
+		 * to see what happened.
 		 */
 		a->pst = NULL;
 		if ((ret = _archive_write_disk_lazy_stat(a)) != ARCHIVE_OK)
 			return (ret);
-		if (a->st.st_size != a->filesize) {
+		/* We can use lseek()/write() to extend the file if
+		 * ftruncate didn't work or isn't available. */
+		if (a->st.st_size < a->filesize) {
 			const char nul = '\0';
-			if (lseek(a->fd, a->st.st_size - 1, SEEK_SET) < 0) {
+			if (lseek(a->fd, a->filesize - 1, SEEK_SET) < 0) {
 				archive_set_error(&a->archive, errno,
 				    "Seek failed");
 				return (ARCHIVE_FATAL);